SlideShare une entreprise Scribd logo
1  sur  70
Télécharger pour lire hors ligne
9. Time
WHAT’S TIME?
HOW CAN WE MESURE IT?
   WHERE ARE WE?
   WHEN ARE WE?
THE SOLAR SYSTEM

  THE SUN
  9 MAJOR PLANETS
  PLANETARY MOONS
  2000 MINOR PLANETS & ATEROIDS
9. Time
9. Time
9. Time
9. Time
KEPPLER LAWS:
   1.   Each planet moves in an elliptical orbit with the Sun in
        one foci
2.   The straight line joining the Sun and any planet
     sweeps out equal areas in equal time intervals
3. K . SP² = d³
RELATIVE POSITION EARTH – SUN:
  •   PERIHELION  Closest to the Sun
  •   APHELION  Furtherst from the Sun
EARTH’S MOVEMENTS:
   1.   ROTATION (West -> East)  DIURNAL CHANGES
   2.    ANNUAL MOVEMENT (Orbit)  Due also to axis
        inclination in relation to the Sun’s ecliptic. SEASONAL
        CHANGES
        Elliptic movement arround Sun (one foci)
                   IMPORTANT POSITIONS (N.H):
                          SUMMER SOLSTICE             21st June
                          WINTER SOLSTICE             22nd Dec
                          VERNAL or SPRING EQUINOX    21st March
                          AUTUMNAL EQUINOX            23rd Sep
9. Time
9. Time
9. Time
9. Time
IMPORTANT FEATURES:

• Earth axis tilted 66.5º to the plane of the ECLIPTIC.
               ANGLE BETWEEN EQ AND ECLIPTIC = 23.5º


           Paralel of latitude directly underneath the Sun rays changes
                                        slowly



                   SEASONAL CHANGES OVER THE YEAR
                            (DECLINATION)
IMPORTANT FEATURES:
     DECLINATION
Sun at:

• Most SOUTHERLY point (Tropic of Capricorn): 22nd Dec
                    N.H  WINTER SOLSTICE
                    S.H.  SUMMER SOLSTICE

• Most NORTHERLY point (Tropic of Capricorn): 21st June

                    N.H.  SUMMER SOLSTICE
                    S.H.  WINTER SOLSTICE
Sun crosses the Equator:

• From South to North: 21st of March

                  N.H.  SPRING or VERNAL EQUINOX
                  S.H.  AUTUMN EQUINOX

• From North to South: 23rd of September

                   N.H.  AUTUMN EQUINOX
                   S.H.  SPRING or VERNAL EQUINOX
DEFINITION: The time interval that elapses between two
      succesive transits of a heavenly body across the same
      meridian

        Earth rotation ≈ Rotation of celestial sphere




    Heavenly bodies are continuosly crossing an observer’s
            meridian in an East – West direction
Any heavenly body could be used as a timekeeper



Sun not the perfect one because its apparent speed along
                    the ecliptic varies



    SIDEREAL DAY: Measured against any star (Unable to
           relate it with light darkness periods)
    SOLAR DAY: Measured against the Sun
9. Time
APPARENT SOLAR DAY:
     Time interval that elapses between two successive
     transits of the actual Sun across the same meridian


           APPARENT SOLAR TIME: Time based upon
                the Sun as it appears on the sky,
                taking as reference its transit from
                the observers antimeridian.
                Measured in refrence to the
                apparent Sun on a particular
                meridian.
The Sun’s real movement on the ecliptic per day is more than
                360º. There are two reasons:

  • The Earth is moving on an ecliptic motion arround the
             Sun
  • The Earth’s speed is varying arround its orbit
THE MEAN SOLAR DAY
 Due to the fact of the Sun not moving equally on the sky
every day , and also to the fact of this variation not being
constant, we can’t consider the Real Sun giving us a practical
unit of measurement


To overcome this dificulty  IMAGINARY BODY = MEAN SUN.
       Its assumed to move along the celestial equator (ecliptic)
       at a uniform speed, and to complete one revolution in
       nearly the mean time it takes to the true Sun to
complete       one revolution in the ecliptic
THE MEAN SOLAR DAY

DEFINITION: Time interval between two succesive transits of
       the mean Sun across the same meridian. CIVIL DAY



          360º of longitude = 24 Mean solar hours
            15º of longitude = 1 Mean solar hour

     NOTE: Difference between Apparent and Mean days is nearly a
                               minute
EQUATION OF TIME
DEFINITION: Relation in terms of time between the Apparent
       time and Mean time for a specific day. Varies
       throughout the year and its due to the eccentricy* of
       the Earth’s elliptical orbit arround the Sun

    EQUATION OF TIME = APPARENT TIME – MEAN TIME


ECCENTRICITY = Relationship between the major and minor axes of an
ellipse. Meassures how simmilar an ellipse and a circumference are
EQUATION OF TIME
SIDERAL YEAR: Time the Earth takes to complete a full orbit
      arround the Sun measured against a distant star . 365d
      5h 48min 45 sec. For ease, 365days and 6hours

CALENDAR YEAR: Taken as 365days. Kept in accordance with
     the calendar year by adding 1 day to the year each 4
     years (Leap year)
DEFINITION: Time according to the Mean Sun.
      The angle, converted to time, from the observers
      antimeridian westwards to the Mean Sun

                 Diff Long (A-B)  Diff of LMT (A-B)


  NOTE: A 24h period implies a 360º rotation and, because of this, 15º rotation
        (CHLong) is a 1h change in time  Conversion Arc to time Chart
9. Time
UNIVERSAL CO-ORDINATED TIME (UTC/GMT)
     LMT at the Greenwich meridian (0ºE/W). Is the time
     reference for aviation.



 TIME CONVERSION CALCULUS BETWEEN ANY LMT AND UTC



 Where a meridian is:
   • East of Greenwich  Time is LATER       Long WEST, UTC BEST
   • West of Greenwich  Time is EARLIER     Long EAST, UTC LEAST
DIFFERENCE BETWEEN UTC AND GMT:

        Co-ordinated Universtal Time (UTC) changes at a
constant rate and is regulated agains the INTERNATIONAL
ATOMIC TIME (IAT), which is derived from atomic clocks.
UTC is regularly corrected to match GMT (LMT at the
Greenwich Meridian), but those corrections are very small.

           For practical purposes, UTC equals GMT
UNIVERSAL CO-ORDINATED TIME (UTC/GMT):

         Example 1: What’s the difference in LMT between London
                 Heathrow (51º 28’N 000º27’W) and Kennedy Intl (New
                 York) (40º38’N 073º46’W)

1.   CHLong = 73º46’ – 000º27’ = 73º 19’
2.   Knowing that 15º change in longitude equal 1h change in time:
        73º19’ = 73.316º  73.316º · (1h/15º) = 4.887h = 4h 53min
UNIVERSAL CO-ORDINATED TIME (UTC):

         Example 2: If the LMT in Goose Bay (060ºW) is 1200, what is
                 the UTC?

1.   CHLong = 060ºw – 000ºE/W = 60º
2.   60º · (1h/15º) = 4.0h
3.   As Goose Bay is West (Longitude west UTC best) we have to add this
     difference in LMT to the time of Goose Bay to find the UTC
         1200 + 4 = 1600
DEFINITION:
      Earth is divided into 24 time zones, each of 15º of
      longitude in width.
      Each zone has 1h difference to the one right next to it
      and uses the LMT of its central meridian as time
      reference.
9. Time
FEATURES:

  • Each zone is designated by letters: zone 0 = Z,
      zone -1 = A,…
  • Eastern longitudes are numbered with negative zone
    numbers
  • Western longitudes are numbered with positive zone
    numbers
  • Mathematically UTC = Zone Time + Zone number
9. Time
DEFINITION:
      Time stated for a determined area in accordance with
      State’s frontiers of natural geographical borders.

       Sometimes listed as LOCAL TIME (LT)

       Countries like USA, Canada or Australia have such a
       large east-west extent that need to use multiple time
       belts, each of them having its own Standard Time
9. Time
DIFFERENCE BETWEEN STANDARD AND ZONE TIME
STANDARD TIME TABLES (Book):

      LIST 1: Contains places where ST is normally fast on
              UTC (East of Greenwich Meridian)

      LIST 2:Contains places where ST is normally UTC/GMT

      LIST 3: Contains places where ST is normally slow on
              UTC (West of Greenwich Meridian)
INTERNATIONAL DATE LINE:
        Whenever taking into account LMT, and moving
westwards there will be a moment in which we will get to the
Greenwich anti-meridian. There its supposed to be a -12h
LMT.
        If we do the same eastwards, will get to the same
point, but with a supposed time of +12h.
        Whenever we cross the 180ºE/W meridian we will
be, then, changing day, and depending on which direction we
are crossing it to, we will have to change date foreward or
backwards
INTERNATIONAL DATE LINE:
INTERNATIONAL DATE LINE:
9. Time
9. Time
9. Time
9. Time
EXPLANATION:

     Most countries adjust their local time (ST) according to
            the season of the year. When this is done, local
            time is advanced one hour in the spring, and
            the Daylight Saving Time (Also called Summer
            Time) is in efecct. In autumn the clocks are set
            back to ST again  Energy saving

      Countries following this rule will be specifyied on the
                ST Lists by and asterisk *
9. Time
9. Time
9. Time
9. Time
9. Time
9. Time
SUNRISE: Time moment of the day in which the upper limb of
      the Sun is coincident with the observer’s visible
      horizon, and the Sun’s tendency is to climb up on the
      sky.
       Centre of the Sun in 0.8º bellow the horizon but due to
       refraction the Sun’s visible before those 0.8º
SUNSET: Time moment of the day in which the upper limb of
      the Sun is coincident with the observer’s visible
      horizon, and the Sun’s tendency is to fall bellow the
      horizon.
       Centre of the Sun in 0.8º bellow the horizon
DEPENDENT ON:

   1.   DATE:

        •   SUMMER  SR earlier and SS later
        •   WINTER  SR later and SS earlier

        Times for SR & SS change slightly from one year to another
DEPENDENT ON:

   2. LATITUDE:

     Times for SR and SS change by several min each 3-
     day period and this change is more pronounced the
     higher the atitude.
     For one particular latitude, all places, regardless of
     longitude, will have the same LMT for SR and SS
DEFINITION:

       Period of the day before sunrise and after sunset in
which there is still sifficient illumination for normal daylight
operations to continue.
Period divided into 3 stages:

       CIVIL TWILIGHT – Time period between the moment of the
               Sun being 6º bellow horizon until SR. Or betwee SS and
               6º bellow horizon. SETS LIMIT FOR DAY-FLYING

       NAUTICAL TWILIGHT - Time period betwee the 12º-bellow-
               horizon position of the Sun until the Civil twilight begins

       ASTRONOMICAL TWILIGHT – Time period between the
               moment in which the Sun is 18º bellow horizon to the
               moment the Nautical twilight begins
9. Time
1. VARIATION OF TWILIGHT WITH LATITUDE:

      LOW LATITUDES: At the Tropics the Sun rises and sets
            at almost 90º to the horizon. The period is
            quite short because the way traveled is the
            shortest possible
      HIGH LATITUDES: The angle of the Sun approaching
            the horizon is tilted, the path followed until
            those 6º bellow horizon will, then, be longer
            and so will be the time taken.

            Lasts more at high latitudes
1. VARIATION OF TWILIGHT WITH LATITUDE:
       LOW LATITUDES
1. VARIATION OF TWILIGHT WITH LATITUDE:
       HIGH LATITUDES
2. VARIATION OF TWILIGHT WITH DECLINATION:

      Generally becomes larger when the Suns declination is
      higher
2. VARIATION OF TWILIGHT WITH DECLINATION

Contenu connexe

Tendances

rotation and revolution
rotation and revolutionrotation and revolution
rotation and revolutionlewis34
 
2 1.1 earth's rotation & revolution
2 1.1 earth's rotation & revolution2 1.1 earth's rotation & revolution
2 1.1 earth's rotation & revolutionSandy Anthony
 
Systems of time measurement (Lecture5)
Systems of time measurement (Lecture5)Systems of time measurement (Lecture5)
Systems of time measurement (Lecture5)Olexiy Pogurelskiy
 
Geosynchronous earth orbit(geo)
Geosynchronous earth orbit(geo)Geosynchronous earth orbit(geo)
Geosynchronous earth orbit(geo)Ananda Mohan
 
Reasons for the seasons notes
Reasons for the seasons notesReasons for the seasons notes
Reasons for the seasons notesmrcoyleteach
 
Keplerian orbital elements (lecture 2)
Keplerian orbital elements (lecture 2)Keplerian orbital elements (lecture 2)
Keplerian orbital elements (lecture 2)Olexiy Pogurelskiy
 
Moon Motions and Eclipses
Moon Motions and EclipsesMoon Motions and Eclipses
Moon Motions and EclipsesShane Riordan
 
Chapter 3 rotation and revolution
Chapter 3   rotation and revolutionChapter 3   rotation and revolution
Chapter 3 rotation and revolutionjaisiebinoy
 
Earth and sun relationships
Earth and sun relationshipsEarth and sun relationships
Earth and sun relationshipslschmidt1170
 
Solar System And Beyond
Solar System And BeyondSolar System And Beyond
Solar System And Beyondneni
 
Time Presentation
Time Presentation Time Presentation
Time Presentation Vj NiroSh
 
Geostationary Satellite
Geostationary SatelliteGeostationary Satellite
Geostationary SatelliteWaqas !!!!
 
Global Positioning System (GPS)
Global Positioning System (GPS) Global Positioning System (GPS)
Global Positioning System (GPS) ManjuChauhan16
 

Tendances (20)

Our Moon
Our MoonOur Moon
Our Moon
 
The sun (more advanced)
The sun (more advanced) The sun (more advanced)
The sun (more advanced)
 
rotation and revolution
rotation and revolutionrotation and revolution
rotation and revolution
 
2 1.1 earth's rotation & revolution
2 1.1 earth's rotation & revolution2 1.1 earth's rotation & revolution
2 1.1 earth's rotation & revolution
 
Systems of time measurement (Lecture5)
Systems of time measurement (Lecture5)Systems of time measurement (Lecture5)
Systems of time measurement (Lecture5)
 
Geosynchronous earth orbit(geo)
Geosynchronous earth orbit(geo)Geosynchronous earth orbit(geo)
Geosynchronous earth orbit(geo)
 
Reasons for the seasons notes
Reasons for the seasons notesReasons for the seasons notes
Reasons for the seasons notes
 
Keplerian orbital elements (lecture 2)
Keplerian orbital elements (lecture 2)Keplerian orbital elements (lecture 2)
Keplerian orbital elements (lecture 2)
 
Coriolis effect
Coriolis effectCoriolis effect
Coriolis effect
 
Moon Motions and Eclipses
Moon Motions and EclipsesMoon Motions and Eclipses
Moon Motions and Eclipses
 
Chapter 3 rotation and revolution
Chapter 3   rotation and revolutionChapter 3   rotation and revolution
Chapter 3 rotation and revolution
 
Earth and sun relationships
Earth and sun relationshipsEarth and sun relationships
Earth and sun relationships
 
The Planet Mercury
The Planet MercuryThe Planet Mercury
The Planet Mercury
 
Solar System And Beyond
Solar System And BeyondSolar System And Beyond
Solar System And Beyond
 
Time Presentation
Time Presentation Time Presentation
Time Presentation
 
Navigation
NavigationNavigation
Navigation
 
Geostationary Satellite
Geostationary SatelliteGeostationary Satellite
Geostationary Satellite
 
The motion of Earth
The motion of EarthThe motion of Earth
The motion of Earth
 
Rotation and revolution of earth
Rotation and revolution of earthRotation and revolution of earth
Rotation and revolution of earth
 
Global Positioning System (GPS)
Global Positioning System (GPS) Global Positioning System (GPS)
Global Positioning System (GPS)
 

Similaire à 9. Time

Earth's physical geo part 1
Earth's physical geo part 1Earth's physical geo part 1
Earth's physical geo part 1nelcole
 
218087672 mokgopa.sun&earth presentation
218087672 mokgopa.sun&earth presentation218087672 mokgopa.sun&earth presentation
218087672 mokgopa.sun&earth presentationTsiamo Mokgopa
 
Geographic Coordinate System.pdf
Geographic Coordinate System.pdfGeographic Coordinate System.pdf
Geographic Coordinate System.pdfTrippinsunshine
 
Space_Cycles_review
Space_Cycles_reviewSpace_Cycles_review
Space_Cycles_reviewDavidSP1996
 
Seasons on earth and other planets explained
Seasons on earth and other planets explained Seasons on earth and other planets explained
Seasons on earth and other planets explained wonderdome
 
Annual Motions - Reasons for Seasons
Annual Motions - Reasons for SeasonsAnnual Motions - Reasons for Seasons
Annual Motions - Reasons for SeasonsBantay's Oceanography
 
Week 6.1 orbital scale climate change
Week 6.1 orbital scale climate changeWeek 6.1 orbital scale climate change
Week 6.1 orbital scale climate changeEmma Carson
 
Earth, sun and moon Interactions
Earth, sun and moon InteractionsEarth, sun and moon Interactions
Earth, sun and moon Interactionsismcook
 
Geodetic Astronomy - MOTION IN THE HEAVENS - EARTH, SUN AND STARS
Geodetic Astronomy - MOTION IN THE HEAVENS - EARTH, SUN AND STARSGeodetic Astronomy - MOTION IN THE HEAVENS - EARTH, SUN AND STARS
Geodetic Astronomy - MOTION IN THE HEAVENS - EARTH, SUN AND STARSAhmed Nassar
 
G7 Science Q4- Week 5 Evidence of Rotation of the Earth.ppt
G7 Science Q4- Week 5 Evidence of Rotation of the Earth.pptG7 Science Q4- Week 5 Evidence of Rotation of the Earth.ppt
G7 Science Q4- Week 5 Evidence of Rotation of the Earth.pptJennineDenielleABatt
 
Earth sun relationship
Earth sun relationshipEarth sun relationship
Earth sun relationshipmontathomas
 
Lab six earth and sun relationships
Lab six earth and sun relationshipsLab six earth and sun relationships
Lab six earth and sun relationshipsLisa Schmidt
 
Solar Radiation Geometry
Solar Radiation GeometrySolar Radiation Geometry
Solar Radiation GeometryVanita Thakkar
 

Similaire à 9. Time (20)

Earth's physical geo part 1
Earth's physical geo part 1Earth's physical geo part 1
Earth's physical geo part 1
 
3.climate
3.climate3.climate
3.climate
 
218087672 mokgopa.sun&earth presentation
218087672 mokgopa.sun&earth presentation218087672 mokgopa.sun&earth presentation
218087672 mokgopa.sun&earth presentation
 
Geographic Coordinate System.pdf
Geographic Coordinate System.pdfGeographic Coordinate System.pdf
Geographic Coordinate System.pdf
 
Space_Cycles_review
Space_Cycles_reviewSpace_Cycles_review
Space_Cycles_review
 
Seasons on earth and other planets explained
Seasons on earth and other planets explained Seasons on earth and other planets explained
Seasons on earth and other planets explained
 
Earth movements.pdf
Earth movements.pdfEarth movements.pdf
Earth movements.pdf
 
Annual Motions - Reasons for Seasons
Annual Motions - Reasons for SeasonsAnnual Motions - Reasons for Seasons
Annual Motions - Reasons for Seasons
 
Week 6.1 orbital scale climate change
Week 6.1 orbital scale climate changeWeek 6.1 orbital scale climate change
Week 6.1 orbital scale climate change
 
Earth, sun and moon Interactions
Earth, sun and moon InteractionsEarth, sun and moon Interactions
Earth, sun and moon Interactions
 
Geodetic Astronomy - MOTION IN THE HEAVENS - EARTH, SUN AND STARS
Geodetic Astronomy - MOTION IN THE HEAVENS - EARTH, SUN AND STARSGeodetic Astronomy - MOTION IN THE HEAVENS - EARTH, SUN AND STARS
Geodetic Astronomy - MOTION IN THE HEAVENS - EARTH, SUN AND STARS
 
G7 Science Q4- Week 5 Evidence of Rotation of the Earth.ppt
G7 Science Q4- Week 5 Evidence of Rotation of the Earth.pptG7 Science Q4- Week 5 Evidence of Rotation of the Earth.ppt
G7 Science Q4- Week 5 Evidence of Rotation of the Earth.ppt
 
Earth sun relationship
Earth sun relationshipEarth sun relationship
Earth sun relationship
 
Seasons
Seasons Seasons
Seasons
 
QUICK GEOGRAPHY (1).pdf
QUICK GEOGRAPHY (1).pdfQUICK GEOGRAPHY (1).pdf
QUICK GEOGRAPHY (1).pdf
 
Geography 6
Geography 6Geography 6
Geography 6
 
The Earth, Rotation and Revolution
The Earth, Rotation and RevolutionThe Earth, Rotation and Revolution
The Earth, Rotation and Revolution
 
Earth in Space
Earth in Space Earth in Space
Earth in Space
 
Lab six earth and sun relationships
Lab six earth and sun relationshipsLab six earth and sun relationships
Lab six earth and sun relationships
 
Solar Radiation Geometry
Solar Radiation GeometrySolar Radiation Geometry
Solar Radiation Geometry
 

Plus de AmenBAL

7 índice
7 índice7 índice
7 índiceAmenBAL
 
8.Charts
8.Charts8.Charts
8.ChartsAmenBAL
 
Magnetism
MagnetismMagnetism
MagnetismAmenBAL
 
5. Triangle of velocities
5. Triangle of velocities5. Triangle of velocities
5. Triangle of velocitiesAmenBAL
 
6. CR-3 Wind Side 2/2
6. CR-3 Wind Side 2/26. CR-3 Wind Side 2/2
6. CR-3 Wind Side 2/2AmenBAL
 
6. CR 3 Wind Side 1/2
6. CR 3 Wind Side 1/26. CR 3 Wind Side 1/2
6. CR 3 Wind Side 1/2AmenBAL
 
5. Magnetismo
5. Magnetismo5. Magnetismo
5. MagnetismoAmenBAL
 
4. Dirección
4. Dirección4. Dirección
4. DirecciónAmenBAL
 
3. Carta OACI 1:500.000
3. Carta OACI 1:500.0003. Carta OACI 1:500.000
3. Carta OACI 1:500.000AmenBAL
 
2. Mapas
2. Mapas2. Mapas
2. MapasAmenBAL
 
1.Froma de la tierra
1.Froma de la tierra1.Froma de la tierra
1.Froma de la tierraAmenBAL
 
CR-3 Computer Side
CR-3 Computer SideCR-3 Computer Side
CR-3 Computer SideAmenBAL
 
Cr3 computer side
Cr3 computer sideCr3 computer side
Cr3 computer sideAmenBAL
 
Cr 3 ETAS
Cr 3 ETASCr 3 ETAS
Cr 3 ETASAmenBAL
 
5. triangle of velocities
5. triangle of velocities5. triangle of velocities
5. triangle of velocitiesAmenBAL
 
4. Speeds
4. Speeds4. Speeds
4. SpeedsAmenBAL
 
3.Directions
3.Directions3.Directions
3.DirectionsAmenBAL
 
2.Position on the Earth
2.Position on the Earth2.Position on the Earth
2.Position on the EarthAmenBAL
 
1.the form of the earth
1.the form of the earth1.the form of the earth
1.the form of the earthAmenBAL
 
0.Introduction
0.Introduction0.Introduction
0.IntroductionAmenBAL
 

Plus de AmenBAL (20)

7 índice
7 índice7 índice
7 índice
 
8.Charts
8.Charts8.Charts
8.Charts
 
Magnetism
MagnetismMagnetism
Magnetism
 
5. Triangle of velocities
5. Triangle of velocities5. Triangle of velocities
5. Triangle of velocities
 
6. CR-3 Wind Side 2/2
6. CR-3 Wind Side 2/26. CR-3 Wind Side 2/2
6. CR-3 Wind Side 2/2
 
6. CR 3 Wind Side 1/2
6. CR 3 Wind Side 1/26. CR 3 Wind Side 1/2
6. CR 3 Wind Side 1/2
 
5. Magnetismo
5. Magnetismo5. Magnetismo
5. Magnetismo
 
4. Dirección
4. Dirección4. Dirección
4. Dirección
 
3. Carta OACI 1:500.000
3. Carta OACI 1:500.0003. Carta OACI 1:500.000
3. Carta OACI 1:500.000
 
2. Mapas
2. Mapas2. Mapas
2. Mapas
 
1.Froma de la tierra
1.Froma de la tierra1.Froma de la tierra
1.Froma de la tierra
 
CR-3 Computer Side
CR-3 Computer SideCR-3 Computer Side
CR-3 Computer Side
 
Cr3 computer side
Cr3 computer sideCr3 computer side
Cr3 computer side
 
Cr 3 ETAS
Cr 3 ETASCr 3 ETAS
Cr 3 ETAS
 
5. triangle of velocities
5. triangle of velocities5. triangle of velocities
5. triangle of velocities
 
4. Speeds
4. Speeds4. Speeds
4. Speeds
 
3.Directions
3.Directions3.Directions
3.Directions
 
2.Position on the Earth
2.Position on the Earth2.Position on the Earth
2.Position on the Earth
 
1.the form of the earth
1.the form of the earth1.the form of the earth
1.the form of the earth
 
0.Introduction
0.Introduction0.Introduction
0.Introduction
 

Dernier

Ultra structure and life cycle of Plasmodium.pptx
Ultra structure and life cycle of Plasmodium.pptxUltra structure and life cycle of Plasmodium.pptx
Ultra structure and life cycle of Plasmodium.pptxDr. Asif Anas
 
NOTES OF DRUGS ACTING ON NERVOUS SYSTEM .pdf
NOTES OF DRUGS ACTING ON NERVOUS SYSTEM .pdfNOTES OF DRUGS ACTING ON NERVOUS SYSTEM .pdf
NOTES OF DRUGS ACTING ON NERVOUS SYSTEM .pdfSumit Tiwari
 
DUST OF SNOW_BY ROBERT FROST_EDITED BY_ TANMOY MISHRA
DUST OF SNOW_BY ROBERT FROST_EDITED BY_ TANMOY MISHRADUST OF SNOW_BY ROBERT FROST_EDITED BY_ TANMOY MISHRA
DUST OF SNOW_BY ROBERT FROST_EDITED BY_ TANMOY MISHRATanmoy Mishra
 
Easter in the USA presentation by Chloe.
Easter in the USA presentation by Chloe.Easter in the USA presentation by Chloe.
Easter in the USA presentation by Chloe.EnglishCEIPdeSigeiro
 
Maximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdf
Maximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdfMaximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdf
Maximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdfTechSoup
 
3.19.24 Urban Uprisings and the Chicago Freedom Movement.pptx
3.19.24 Urban Uprisings and the Chicago Freedom Movement.pptx3.19.24 Urban Uprisings and the Chicago Freedom Movement.pptx
3.19.24 Urban Uprisings and the Chicago Freedom Movement.pptxmary850239
 
Drug Information Services- DIC and Sources.
Drug Information Services- DIC and Sources.Drug Information Services- DIC and Sources.
Drug Information Services- DIC and Sources.raviapr7
 
PISA-VET launch_El Iza Mohamedou_19 March 2024.pptx
PISA-VET launch_El Iza Mohamedou_19 March 2024.pptxPISA-VET launch_El Iza Mohamedou_19 March 2024.pptx
PISA-VET launch_El Iza Mohamedou_19 March 2024.pptxEduSkills OECD
 
How to Make a Field read-only in Odoo 17
How to Make a Field read-only in Odoo 17How to Make a Field read-only in Odoo 17
How to Make a Field read-only in Odoo 17Celine George
 
How to Solve Singleton Error in the Odoo 17
How to Solve Singleton Error in the  Odoo 17How to Solve Singleton Error in the  Odoo 17
How to Solve Singleton Error in the Odoo 17Celine George
 
M-2- General Reactions of amino acids.pptx
M-2- General Reactions of amino acids.pptxM-2- General Reactions of amino acids.pptx
M-2- General Reactions of amino acids.pptxDr. Santhosh Kumar. N
 
Quality Assurance_GOOD LABORATORY PRACTICE
Quality Assurance_GOOD LABORATORY PRACTICEQuality Assurance_GOOD LABORATORY PRACTICE
Quality Assurance_GOOD LABORATORY PRACTICESayali Powar
 
Patient Counselling. Definition of patient counseling; steps involved in pati...
Patient Counselling. Definition of patient counseling; steps involved in pati...Patient Counselling. Definition of patient counseling; steps involved in pati...
Patient Counselling. Definition of patient counseling; steps involved in pati...raviapr7
 
Presentation on the Basics of Writing. Writing a Paragraph
Presentation on the Basics of Writing. Writing a ParagraphPresentation on the Basics of Writing. Writing a Paragraph
Presentation on the Basics of Writing. Writing a ParagraphNetziValdelomar1
 
Clinical Pharmacy Introduction to Clinical Pharmacy, Concept of clinical pptx
Clinical Pharmacy  Introduction to Clinical Pharmacy, Concept of clinical pptxClinical Pharmacy  Introduction to Clinical Pharmacy, Concept of clinical pptx
Clinical Pharmacy Introduction to Clinical Pharmacy, Concept of clinical pptxraviapr7
 
How to Add Existing Field in One2Many Tree View in Odoo 17
How to Add Existing Field in One2Many Tree View in Odoo 17How to Add Existing Field in One2Many Tree View in Odoo 17
How to Add Existing Field in One2Many Tree View in Odoo 17Celine George
 
Patterns of Written Texts Across Disciplines.pptx
Patterns of Written Texts Across Disciplines.pptxPatterns of Written Texts Across Disciplines.pptx
Patterns of Written Texts Across Disciplines.pptxMYDA ANGELICA SUAN
 
Prescribed medication order and communication skills.pptx
Prescribed medication order and communication skills.pptxPrescribed medication order and communication skills.pptx
Prescribed medication order and communication skills.pptxraviapr7
 

Dernier (20)

Ultra structure and life cycle of Plasmodium.pptx
Ultra structure and life cycle of Plasmodium.pptxUltra structure and life cycle of Plasmodium.pptx
Ultra structure and life cycle of Plasmodium.pptx
 
Finals of Kant get Marx 2.0 : a general politics quiz
Finals of Kant get Marx 2.0 : a general politics quizFinals of Kant get Marx 2.0 : a general politics quiz
Finals of Kant get Marx 2.0 : a general politics quiz
 
NOTES OF DRUGS ACTING ON NERVOUS SYSTEM .pdf
NOTES OF DRUGS ACTING ON NERVOUS SYSTEM .pdfNOTES OF DRUGS ACTING ON NERVOUS SYSTEM .pdf
NOTES OF DRUGS ACTING ON NERVOUS SYSTEM .pdf
 
DUST OF SNOW_BY ROBERT FROST_EDITED BY_ TANMOY MISHRA
DUST OF SNOW_BY ROBERT FROST_EDITED BY_ TANMOY MISHRADUST OF SNOW_BY ROBERT FROST_EDITED BY_ TANMOY MISHRA
DUST OF SNOW_BY ROBERT FROST_EDITED BY_ TANMOY MISHRA
 
Easter in the USA presentation by Chloe.
Easter in the USA presentation by Chloe.Easter in the USA presentation by Chloe.
Easter in the USA presentation by Chloe.
 
Maximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdf
Maximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdfMaximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdf
Maximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdf
 
3.19.24 Urban Uprisings and the Chicago Freedom Movement.pptx
3.19.24 Urban Uprisings and the Chicago Freedom Movement.pptx3.19.24 Urban Uprisings and the Chicago Freedom Movement.pptx
3.19.24 Urban Uprisings and the Chicago Freedom Movement.pptx
 
Drug Information Services- DIC and Sources.
Drug Information Services- DIC and Sources.Drug Information Services- DIC and Sources.
Drug Information Services- DIC and Sources.
 
PISA-VET launch_El Iza Mohamedou_19 March 2024.pptx
PISA-VET launch_El Iza Mohamedou_19 March 2024.pptxPISA-VET launch_El Iza Mohamedou_19 March 2024.pptx
PISA-VET launch_El Iza Mohamedou_19 March 2024.pptx
 
Personal Resilience in Project Management 2 - TV Edit 1a.pdf
Personal Resilience in Project Management 2 - TV Edit 1a.pdfPersonal Resilience in Project Management 2 - TV Edit 1a.pdf
Personal Resilience in Project Management 2 - TV Edit 1a.pdf
 
How to Make a Field read-only in Odoo 17
How to Make a Field read-only in Odoo 17How to Make a Field read-only in Odoo 17
How to Make a Field read-only in Odoo 17
 
How to Solve Singleton Error in the Odoo 17
How to Solve Singleton Error in the  Odoo 17How to Solve Singleton Error in the  Odoo 17
How to Solve Singleton Error in the Odoo 17
 
M-2- General Reactions of amino acids.pptx
M-2- General Reactions of amino acids.pptxM-2- General Reactions of amino acids.pptx
M-2- General Reactions of amino acids.pptx
 
Quality Assurance_GOOD LABORATORY PRACTICE
Quality Assurance_GOOD LABORATORY PRACTICEQuality Assurance_GOOD LABORATORY PRACTICE
Quality Assurance_GOOD LABORATORY PRACTICE
 
Patient Counselling. Definition of patient counseling; steps involved in pati...
Patient Counselling. Definition of patient counseling; steps involved in pati...Patient Counselling. Definition of patient counseling; steps involved in pati...
Patient Counselling. Definition of patient counseling; steps involved in pati...
 
Presentation on the Basics of Writing. Writing a Paragraph
Presentation on the Basics of Writing. Writing a ParagraphPresentation on the Basics of Writing. Writing a Paragraph
Presentation on the Basics of Writing. Writing a Paragraph
 
Clinical Pharmacy Introduction to Clinical Pharmacy, Concept of clinical pptx
Clinical Pharmacy  Introduction to Clinical Pharmacy, Concept of clinical pptxClinical Pharmacy  Introduction to Clinical Pharmacy, Concept of clinical pptx
Clinical Pharmacy Introduction to Clinical Pharmacy, Concept of clinical pptx
 
How to Add Existing Field in One2Many Tree View in Odoo 17
How to Add Existing Field in One2Many Tree View in Odoo 17How to Add Existing Field in One2Many Tree View in Odoo 17
How to Add Existing Field in One2Many Tree View in Odoo 17
 
Patterns of Written Texts Across Disciplines.pptx
Patterns of Written Texts Across Disciplines.pptxPatterns of Written Texts Across Disciplines.pptx
Patterns of Written Texts Across Disciplines.pptx
 
Prescribed medication order and communication skills.pptx
Prescribed medication order and communication skills.pptxPrescribed medication order and communication skills.pptx
Prescribed medication order and communication skills.pptx
 

9. Time

  • 2. WHAT’S TIME? HOW CAN WE MESURE IT? WHERE ARE WE? WHEN ARE WE?
  • 3. THE SOLAR SYSTEM THE SUN 9 MAJOR PLANETS PLANETARY MOONS 2000 MINOR PLANETS & ATEROIDS
  • 8. KEPPLER LAWS: 1. Each planet moves in an elliptical orbit with the Sun in one foci
  • 9. 2. The straight line joining the Sun and any planet sweeps out equal areas in equal time intervals
  • 10. 3. K . SP² = d³
  • 11. RELATIVE POSITION EARTH – SUN: • PERIHELION  Closest to the Sun • APHELION  Furtherst from the Sun
  • 12. EARTH’S MOVEMENTS: 1. ROTATION (West -> East)  DIURNAL CHANGES 2. ANNUAL MOVEMENT (Orbit)  Due also to axis inclination in relation to the Sun’s ecliptic. SEASONAL CHANGES Elliptic movement arround Sun (one foci) IMPORTANT POSITIONS (N.H): SUMMER SOLSTICE  21st June WINTER SOLSTICE  22nd Dec VERNAL or SPRING EQUINOX  21st March AUTUMNAL EQUINOX  23rd Sep
  • 17. IMPORTANT FEATURES: • Earth axis tilted 66.5º to the plane of the ECLIPTIC. ANGLE BETWEEN EQ AND ECLIPTIC = 23.5º Paralel of latitude directly underneath the Sun rays changes slowly SEASONAL CHANGES OVER THE YEAR (DECLINATION)
  • 18. IMPORTANT FEATURES: DECLINATION
  • 19. Sun at: • Most SOUTHERLY point (Tropic of Capricorn): 22nd Dec N.H  WINTER SOLSTICE S.H.  SUMMER SOLSTICE • Most NORTHERLY point (Tropic of Capricorn): 21st June N.H.  SUMMER SOLSTICE S.H.  WINTER SOLSTICE
  • 20. Sun crosses the Equator: • From South to North: 21st of March N.H.  SPRING or VERNAL EQUINOX S.H.  AUTUMN EQUINOX • From North to South: 23rd of September N.H.  AUTUMN EQUINOX S.H.  SPRING or VERNAL EQUINOX
  • 21. DEFINITION: The time interval that elapses between two succesive transits of a heavenly body across the same meridian Earth rotation ≈ Rotation of celestial sphere Heavenly bodies are continuosly crossing an observer’s meridian in an East – West direction
  • 22. Any heavenly body could be used as a timekeeper Sun not the perfect one because its apparent speed along the ecliptic varies SIDEREAL DAY: Measured against any star (Unable to relate it with light darkness periods) SOLAR DAY: Measured against the Sun
  • 24. APPARENT SOLAR DAY: Time interval that elapses between two successive transits of the actual Sun across the same meridian APPARENT SOLAR TIME: Time based upon the Sun as it appears on the sky, taking as reference its transit from the observers antimeridian. Measured in refrence to the apparent Sun on a particular meridian.
  • 25. The Sun’s real movement on the ecliptic per day is more than 360º. There are two reasons: • The Earth is moving on an ecliptic motion arround the Sun • The Earth’s speed is varying arround its orbit
  • 26. THE MEAN SOLAR DAY Due to the fact of the Sun not moving equally on the sky every day , and also to the fact of this variation not being constant, we can’t consider the Real Sun giving us a practical unit of measurement To overcome this dificulty  IMAGINARY BODY = MEAN SUN. Its assumed to move along the celestial equator (ecliptic) at a uniform speed, and to complete one revolution in nearly the mean time it takes to the true Sun to complete one revolution in the ecliptic
  • 27. THE MEAN SOLAR DAY DEFINITION: Time interval between two succesive transits of the mean Sun across the same meridian. CIVIL DAY 360º of longitude = 24 Mean solar hours 15º of longitude = 1 Mean solar hour NOTE: Difference between Apparent and Mean days is nearly a minute
  • 28. EQUATION OF TIME DEFINITION: Relation in terms of time between the Apparent time and Mean time for a specific day. Varies throughout the year and its due to the eccentricy* of the Earth’s elliptical orbit arround the Sun EQUATION OF TIME = APPARENT TIME – MEAN TIME ECCENTRICITY = Relationship between the major and minor axes of an ellipse. Meassures how simmilar an ellipse and a circumference are
  • 30. SIDERAL YEAR: Time the Earth takes to complete a full orbit arround the Sun measured against a distant star . 365d 5h 48min 45 sec. For ease, 365days and 6hours CALENDAR YEAR: Taken as 365days. Kept in accordance with the calendar year by adding 1 day to the year each 4 years (Leap year)
  • 31. DEFINITION: Time according to the Mean Sun. The angle, converted to time, from the observers antimeridian westwards to the Mean Sun Diff Long (A-B)  Diff of LMT (A-B) NOTE: A 24h period implies a 360º rotation and, because of this, 15º rotation (CHLong) is a 1h change in time  Conversion Arc to time Chart
  • 33. UNIVERSAL CO-ORDINATED TIME (UTC/GMT) LMT at the Greenwich meridian (0ºE/W). Is the time reference for aviation. TIME CONVERSION CALCULUS BETWEEN ANY LMT AND UTC Where a meridian is: • East of Greenwich  Time is LATER Long WEST, UTC BEST • West of Greenwich  Time is EARLIER Long EAST, UTC LEAST
  • 34. DIFFERENCE BETWEEN UTC AND GMT: Co-ordinated Universtal Time (UTC) changes at a constant rate and is regulated agains the INTERNATIONAL ATOMIC TIME (IAT), which is derived from atomic clocks. UTC is regularly corrected to match GMT (LMT at the Greenwich Meridian), but those corrections are very small. For practical purposes, UTC equals GMT
  • 35. UNIVERSAL CO-ORDINATED TIME (UTC/GMT): Example 1: What’s the difference in LMT between London Heathrow (51º 28’N 000º27’W) and Kennedy Intl (New York) (40º38’N 073º46’W) 1. CHLong = 73º46’ – 000º27’ = 73º 19’ 2. Knowing that 15º change in longitude equal 1h change in time: 73º19’ = 73.316º  73.316º · (1h/15º) = 4.887h = 4h 53min
  • 36. UNIVERSAL CO-ORDINATED TIME (UTC): Example 2: If the LMT in Goose Bay (060ºW) is 1200, what is the UTC? 1. CHLong = 060ºw – 000ºE/W = 60º 2. 60º · (1h/15º) = 4.0h 3. As Goose Bay is West (Longitude west UTC best) we have to add this difference in LMT to the time of Goose Bay to find the UTC 1200 + 4 = 1600
  • 37. DEFINITION: Earth is divided into 24 time zones, each of 15º of longitude in width. Each zone has 1h difference to the one right next to it and uses the LMT of its central meridian as time reference.
  • 39. FEATURES: • Each zone is designated by letters: zone 0 = Z, zone -1 = A,… • Eastern longitudes are numbered with negative zone numbers • Western longitudes are numbered with positive zone numbers • Mathematically UTC = Zone Time + Zone number
  • 41. DEFINITION: Time stated for a determined area in accordance with State’s frontiers of natural geographical borders. Sometimes listed as LOCAL TIME (LT) Countries like USA, Canada or Australia have such a large east-west extent that need to use multiple time belts, each of them having its own Standard Time
  • 44. STANDARD TIME TABLES (Book): LIST 1: Contains places where ST is normally fast on UTC (East of Greenwich Meridian) LIST 2:Contains places where ST is normally UTC/GMT LIST 3: Contains places where ST is normally slow on UTC (West of Greenwich Meridian)
  • 45. INTERNATIONAL DATE LINE: Whenever taking into account LMT, and moving westwards there will be a moment in which we will get to the Greenwich anti-meridian. There its supposed to be a -12h LMT. If we do the same eastwards, will get to the same point, but with a supposed time of +12h. Whenever we cross the 180ºE/W meridian we will be, then, changing day, and depending on which direction we are crossing it to, we will have to change date foreward or backwards
  • 52. EXPLANATION: Most countries adjust their local time (ST) according to the season of the year. When this is done, local time is advanced one hour in the spring, and the Daylight Saving Time (Also called Summer Time) is in efecct. In autumn the clocks are set back to ST again  Energy saving Countries following this rule will be specifyied on the ST Lists by and asterisk *
  • 59. SUNRISE: Time moment of the day in which the upper limb of the Sun is coincident with the observer’s visible horizon, and the Sun’s tendency is to climb up on the sky. Centre of the Sun in 0.8º bellow the horizon but due to refraction the Sun’s visible before those 0.8º
  • 60. SUNSET: Time moment of the day in which the upper limb of the Sun is coincident with the observer’s visible horizon, and the Sun’s tendency is to fall bellow the horizon. Centre of the Sun in 0.8º bellow the horizon
  • 61. DEPENDENT ON: 1. DATE: • SUMMER  SR earlier and SS later • WINTER  SR later and SS earlier Times for SR & SS change slightly from one year to another
  • 62. DEPENDENT ON: 2. LATITUDE: Times for SR and SS change by several min each 3- day period and this change is more pronounced the higher the atitude. For one particular latitude, all places, regardless of longitude, will have the same LMT for SR and SS
  • 63. DEFINITION: Period of the day before sunrise and after sunset in which there is still sifficient illumination for normal daylight operations to continue.
  • 64. Period divided into 3 stages: CIVIL TWILIGHT – Time period between the moment of the Sun being 6º bellow horizon until SR. Or betwee SS and 6º bellow horizon. SETS LIMIT FOR DAY-FLYING NAUTICAL TWILIGHT - Time period betwee the 12º-bellow- horizon position of the Sun until the Civil twilight begins ASTRONOMICAL TWILIGHT – Time period between the moment in which the Sun is 18º bellow horizon to the moment the Nautical twilight begins
  • 66. 1. VARIATION OF TWILIGHT WITH LATITUDE: LOW LATITUDES: At the Tropics the Sun rises and sets at almost 90º to the horizon. The period is quite short because the way traveled is the shortest possible HIGH LATITUDES: The angle of the Sun approaching the horizon is tilted, the path followed until those 6º bellow horizon will, then, be longer and so will be the time taken. Lasts more at high latitudes
  • 67. 1. VARIATION OF TWILIGHT WITH LATITUDE: LOW LATITUDES
  • 68. 1. VARIATION OF TWILIGHT WITH LATITUDE: HIGH LATITUDES
  • 69. 2. VARIATION OF TWILIGHT WITH DECLINATION: Generally becomes larger when the Suns declination is higher
  • 70. 2. VARIATION OF TWILIGHT WITH DECLINATION